Thurber's Beardtongue [Penstemon thurberi Torr.]
Listing CNPS List 4 R-E-D Code 1-2-1
State/Federal. Status -- None SCROPHULARIACEAE May-Jul.
Global Rank G4 State Rank S2S3
Distribution: San Diego County, Riverside County, San Bernardino County, Imperial County; New Mexico; Arizona; Nevada; Baja California, Mexico
Habitat: Sonoran Desert Scrub and Pinyon Juniper Woodland are utilized by this showy subshrub. It grows on both sandy and rocky plains. Mecca coarse sandy loams are mapped for the Earthquake Valley site where much of the shrub cover has been grazed, leaving grasslands and occasional shrubs such as Thurber's Beardtongue.
Known Sites: This subshrub was noted growing in Earthquake Valley south of Scissors Crossing. Most individuals are found along the fencing facing Highway S-2, in a cow pasture across the street from limited roadside commercial structures. Herbarium specimens examined are from Mountain Palm Springs, the Los Arenas Ranch in San Felipe Valley, and from Blair Valley for San Diego County; on the Kelso Sand Dunes, and 3 miles southwest of Government Holes on the road to Gold Valley in the Providence Mountains for San Bernardino County; and in Gila and Navajo counties for Arizona. Reported by Shreve and Wiggins eastward into New Mexico, and by Lehr for Arizona.
Five specimens for Baja California are found in the San Diego Natural History Museum to 31 19' North where collected by Moran (SD 53921) on a silty flat 4 miles east of San Matias Pass.
Status: This penstemon is apparently declining in Southern California. Judging from its scattered collection sites, it may have been very sparsely distributed in the region over the last several hundred years. Thurber's Beardtongue is close to extirpation in San Diego County with few colonies apparently still extant. The site in Earthquake Valley is enclosed by fencing and heavily grazed by cattle. It is obviously endangered at this locale. All populations should be protected.
Copyright © May 1994 Craig H. Reiser.
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